Exterior Photo of Building

This Internet Gateway facility in Dublin, Ireland houses a telecommunications hub that has full on-line uninterruptible power supplies. These facilities are fault intolerant and utilise extensive rotary and motor generator power back up.

Diagram of Network Operations Centre

Because of stringent space requirements the Network Operations Centre (NOC) had to be located adjacent to electrical switchgear and above main power cables. In addition, one of the motor generators was located below the NOC room. The strong resultant electromagnetic fields presented a threat to the reliability of the high speed IT equipment.

Graph of ELF Magnetic Fields with Computer Modeling

In the European Union information technology equipment must meet mandatory immunity levels of 1 A/m (12.6 mG) to comply with the EMC Directive. The predicted levels in the NOC room, assessed using computer modelling as shown above and representative measurements, were predicted to exceed 100 mG.

Diagram of NOC with proposed shielding

To ensure compatibility of the environment with the telecommunications equipment specifications FMS designed a magnetic field shielding scheme to accomplish reductions of elevated magnetic field levels in the NOC room, to a 5 mG level. The shielding plan required that layers of shielding material be installed on the interior walls, and on the floor of the room.

Photo of Shielding Project in Progress

This is a partial view of the completed shielding installation in the NOC Room prior to final fit out.

Photo of Installed Shielding, partial view

This is a partial view of the completed shielding installation in the NOC Room prior to final fit out.

3-D Plots of Magnetic Field Before & After Shielding

These are 3D plots of magnetic field conditions at one meter from the floor in the Network Operations Center. The first plot illustrates anticipated elevated magnetic fields as predicted by computer simulation. The second plot shows the actual magnetic field levels after installation of the shielding scheme and with the electrical system on a full load test. The peak value was 5 mG and the average throughout the room was less than 3 mG.

FMS EXPERIENCE

Over its 20 years, FMS has successfully completed hundreds of EMI projects which included a diverse range of consulting and mitigation services.